Status Data File Usage

I'm having a bit of trouble using the Status Bits in a program.
I have a somewhat understanding of what they are and as an internal status for the PLC processor, but I don't really know how to write them to a program or where to plug them in to actually see them work. The only one I really know how to use is the [highlight]S:4[/highlight] as a sequencer bit, but that is it.
Basically, I don't know how to use these data files with compare instructions, MOV instructions...etc.
I realize these may be silly questions to some, but I am sincerely wanting to further my understanding of the more difficult tasks of programming to make myself more useful, as well as, personal satisfaction of knowing that college wasn't for naught.
Thanks,
Jay

Hi jay

First I am of the school there is no silly question, if you don't know you ask.

I am not in front of my pc at present so I can not give you the different address as it is mainly ab 5000" or studio as its now callled" and s7 I use now.
I guess it's ab 500 you are talks by about
There are some status bits that are time based like
1 second on and 1 second off, so this can be used to flash a light by using an xic
Contact. There are status bits that tell you the year, month, day of the week" shown in a recent tread that this is not the in 5000 but you must create it, hour of the day, min of the hour and the second of the minute.
You could use greater than or equal to , in order to get some thing to happen a time like start an item and haven't ready for 8 am Monday to Friday
There are many of this but the help file is good on them
Sorry I don't have the address but as i said it am not at my pc

Donnchadh

There are some status bits that are time based like
1 second in and 1 second off, so this can be used to flash a light by using an xic
Contact.

Click to expand...

Hey Don,
Thanks for the advice. I guess the best way to really find out is to tinker with them and see what happens (not on a running machine of course)

Hi jay

I think you are correct have a go and correct again not on a live machine
Try them out and come back, post your code , ask some more questions here,
As I have said in the past the time and effort people give to strangers here blows my mind.
Donnchadh

You're right! The support I have received from people I've never met on here is phenomenal! This forum rocks!!!!! \m/ \m/

If you are using rslogix500 then there are quite extensive help file for the status bits. In the projects tree at the left of your screen, scroll down to data files and double click S2-STATUS, this will bring up the status files in a structured format, there is a help button which gives a detailed useage of the status words and bits.

Steve

They are used as any other data file (XIO,XIC or as a word or reading & writing to them etc.)

Thanks nehpets!
I pulled the tree up on my screen and printed out the entire S2 population. I was going to write down the more specific bits but man, that would take a loooong time
So I better get to studying all the pertinent data file bits, words and so on.
Thanks again,
Jay

So I better get to studying all the pertinent data file bits, words and so on.

Click to expand...

You probably will not use all of the Status file bits. Some you will need occassionly and you can look them up at that time. You need to be familar with the main headings or tabs in the Status Structured file, and there are a few that you will see often. About one half of the S file bits are used to show the user what is going on in the PLC, while the other half are used for you to set up functions to make the PLC work as you need.

Some Allen Bradley SLC Status File addresses that are useful:

S:1/15 First Pass bit - goes on automatically only during the first scan of the PLC after it is powered up in Run mode, and also when it is switched from Program to Run mode.

S:24 Index Register - contains the offset word used in indexed addressing. This is useful in the older CPUs that do not have indirect addressing.

S:53L - contains the Day of the Week (in some models)
S:39 to S:37 - has the calendar date (in some models).
S:40 to S:41 - contains the time value of the internal clock.
S:4/0 to S:4/15 - the internal clock bits that can be used in your program as flashers.

S:22 = Max scan time, S:23 = Average scan time, and word S:3 has the Current scan time and the Watchdog time setiing in miliseconds.

The "Errors" tab in the Structured S2 Status file has the button to "Clear Major Error". Sooner or later you will need this. There are other bits that can set various Error functions, and also word S:6 contains the Major Error code (tells you what error caused the PLC to halt).

The "Mem Module" tab contains information bits on the optional EEPROM backup memory module, and also bits that set how the memory module is used.

Since I last posted in this particular thread I have been playing around with the Status files, as well as, doing some extensive research on the internal relays.

Most of all, I have been watching how the bits count and move within numerous scenarios. I believe learning this aspect is very important to becoming a successful programmer.

jaywillnot said:

Since I last posted in this particular thread I have been playing around with the Status files, as well as, doing some extensive research on the internal relays.

Most of all, I have been watching how the bits count and move within numerous scenarios. I believe learning this aspect is very important to becoming a successful programmer.

Click to expand...

Key Time Saver:
Don't forget that, when you are viewing the "S" file, as a data file, you can change the format of the view...and that makes things easier to understand.